1. Field of the Invention
The present invention relates to a method for producing L-histidine by fermentation, and particularly to a method for producing L-histidine with a microorganism of the genus Bacillus constructed by a gene splicing technique.
2. Description of the Prior Art
In the past, in order to render a wild strain capable of producing L-histidine from carbohydrates, it has been necessary to induce artificial mutants from the wild strain. In this regard, there are many known L-histidine producing artificial mutants.
Examples of known histidine producing microorganisms include mutants of Brevibacterium and Corynebacterium resistant to 2-thiazolealanine (U.P. Pat. No. 3,716,453), mutant of Corynebacterium resistant to histidine-analog and purine-analog (Japanese Published Examined patent application No. 18798/1977), mutants of Serratia (U.S. Pat. No. 3,902,966), mutants of Proteus (Japanese Published Unexamined patent application No. 92588/1972), mutants of Brevibacterium resistant to 2-thiazolealanine and sulfa-drug (Japanese Published Examined patent application No. 23594/1976).
Another approach to increase the productivity of histidine in microorganisms is suggested in Japanese Published Unexamined patent application No. 165798/1979). In this technique, Escherichia coli strains transformed with a recombinant plasmid DNA and constructed by a gene splicing technique to produce L-histidine are disclosed.
However, it is requested still to produce L-histidine by fermentation in higher efficiency than the known methods.